"This goes against the ethos of the Government’s ­responsibility deal with food businesses, part of which asked manufacturers to cut calories.

“We want the Government to set clear targets for calorie reductions as a priority as part of the responsibility deal.”

Health experts warn that high levels of sugar in everyday foods are contributing to health conditions such as diabetes, heart disease and tooth decay.

Earlier this year the World Health Organisation proposed the recommended daily sugar allowance should be halved to around five heaped teaspoons to help ease the obesity crisis.

Supermarkets insist they are working hard to reduce sugar levels in all their ranges and are making sure nutritional content is clearly labelled on packaging so customers can make “informed decisions”.